1. Field of the Invention
The present invention relates to an image forming apparatus such as an electrophotographic copying machine, facsimile, printer and the like, and more particularly, it relates to an image forming apparatus for reproducing an original having an image including a character portion and an intermediate contrast portion such as a photograph, picture and the like.
2. Related Background Art
Conventionally, in a technical field wherein a multi-gradient image is read and a corresponding signal is outputted, an image forming apparatus having an automatic density converting function such that the density of an image is detected and the density of an output image is controlled on the basis of the detected density value, has been proposed.
However, if a original to be read includes an image having, for example, both a character portion and a photograph portion, simple density conversion results in improper density output. That is to say, with respect to the image of the original including both the character portion and the photograph portion, when the same or similar density conversion is effected regarding the character portion and the photograph portion, even if the reproduction of intermediate contrast of the photograph portion is important, such photograph portion is subjected to the large or heavy density conversion, with the result that the gradient of contrast is deteriorated, thus making optimal reproduction of the image having the intermediate contrast impossible. This problem can be solved by discriminating the character portion from the photograph portion by using an editor (editing apparatus) having the function for designating the image areas on the original with the image forming apparatus. However, in this case, there arise problems that the manipulation of the editor is troublesome and that the apparatus becomes expensive due to the addition of the editor.